Search bioRxiv⌕ Search

Biology subjects

Batista, B.

Publications and source records attributed to Batista, B..

3 recordsLinked to original sources

Leaf microbiome assembly is linked to plant phylogeny

Background and AimsThe plant microbiome is considered as an extended part of the plant genome, and it provides key functions in regulating plant fitness, and stress tolerance. Plants and associated microbiomes have co-evolved over millennia, yet evidence for a strong influence of plant phylogeny in influencing their microbiomes is largely lacking. Our main aims was to identify key drivers of plant microbiome assembly. MethodsHere, we conducted a full factorial experiment that included three levels of soil microbial diversity, five plant species from three functional groups (C3, C4, and C3 nitrogen-fixing), and two moisture availability levels. ResultsOur results showed that host identity and plant functional group exerted the strongest effect on leaf microbial assembly, while root and soil microbiomes showed less sensitivity to host selection. The initial soil microbial diversity and community structure significantly impacted soil and root microbial composition, but not leaf microbiomes. Importantly, we observed significant positive linkage between host phylogeny distance and Bray-Curtis dissimilarity index in leaf microbiomes. This finding was further validated through analysis of microbiome data from seven plant species grown across different field and environmental conditions. Interestingly, there was no significant impact of short-term water stress on plant microbial communities. ConclusionsBy providing empirical evidence for important role of host selection in shaping plant microbiomes, this study advances our fundamental knowledge of plant-microbe interactions and their co-evolutionary relationships, and enhances our ability to develop future tools harnessing plant microbiome to improve plant health and productivity.

microbiology↗

Instant fluorescence lifetime imaging microscopy reveals mechano-metabolic reprogramming of stromal cells in breast cancer peritumoral microenvironments

The breast peritumor microenvironment (pTME) is increasingly recognized as a mediator of breast cancer progression and treatment resistance. However, if and how growth-induced tumor compressive forces (i.e., solid stresses) influence the breast pTME remains unclear. Here we show using instant fluorescence lifetime imaging microscopy (FLIM)--a frequency-domain FLIM system capable of simultaneous image acquisition and instantaneous data processing--that breast tumor-mimicking in vitro compression promotes metabolic changes in stromal cells found in the breast pTME. Namely, compression shifts NIH3T3 fibroblasts and differentiated 3T3-L1 (d3T3-L1) adipocytes toward a more glycolytic state, while it promotes increased oxidative phosphorylation in 3T3-L1 undifferentiated adipocytes. The gold-standard Seahorse extracellular flux assay fails to capture these changes, underscoring the superior sensitivity of instant FLIM in detecting metabolic shifts. We validate these phenotypic findings at the transcriptomic level via RNA sequencing, confirming that compressed fibroblasts downregulate oxidative phosphorylation and upregulate glycolysis compared to uncompressed controls. We further demonstrate that compression induces mitochondrial dysregulation in undifferentiated adipocytes, driven in part by upregulated mitophagy and disrupted fusion dynamics. Finally, we confirm that these stromal cell types recapitulate these distinct metabolic states in human breast cancer patient samples, consistent with our in vitro findings. By elucidating mechano-metabolic interactions occurring at the tumor-host interface, these results will inform the development of innovative mechano-metabolic reprogramming treatment strategies to improve breast cancer patient survival.

biochemistry↗

Mechanical compression induces neuronal apoptosis, reduces synaptic activity, and promotes glial neuroinflammation in mice and humans

Mass effect, characterized by the compression and deformation of neural tissue from space-occupying lesions, can lead to debilitating neurological symptoms and poses a significant clinical challenge. In the primary brain tumor glioblastoma (GBM), we have shown previously that compressive solid stress originating from the growing tumor reduces cerebral blood flow, leads to neuronal loss, increased functional impairment, and poor clinical outcomes. However, the direct effects of compression on neurons and the underlying biophysical mechanisms are poorly understood. Here, using multi-scale compression systems and physiologically relevant in vitro and in vivo models, we find that mechanical compression induces neuronal apoptosis and synapse loss, leading to disrupted neural network activity. This is accompanied by increased HIF-1 signaling and upregulation of downstream stress-adaptive genes in neurons. We further show that compression triggers AP-1-driven gene expression in glial cells, promoting a neuroinflammatory response. Together, these findings reveal that solid stress directly contributes to neuronal dysfunction and inflammation caused by GBM by activating distinct pathways that can be targeted in future studies for neuroprotection. SIGNIFICANCE STATEMENTGlioblastoma (GBM), the deadliest primary brain tumor in adults, exerts physical forces on surrounding brain tissue as it grows, leading to neuronal damage. However, the molecular mechanisms underlying this process are not well understood. In the present study, by applying multiple model systems, we show that mechanical compression triggers neuronal apoptosis, disrupts synaptic communication between neurons, and reduces neural network activity. We also find that compression activates inflammatory pathways in both neurons and glia, further contributing to neuronal damage. These findings reveal how compression exerted by space-occupying lesions may contribute to patients cognitive and motor impairments and suggest new directions for treatment. This work lays the groundwork for therapies that protect neurons from mechanical injury, with relevance not only to GBM but also other neurological diseases that present with mass effect.

neuroscience↗